Lavalier microphones, or “lavs,” are small, close-proximity microphones designed to record the voice. They can be exposed or hidden on talent, usually on the head or chest area. Lavs are ideal for recording dialogue because they’re designed to pick up sounds that are extremely close—which means they also do a great job of quelling the ambience of a location.
Personally, I prefer to record all dialogue with my boom pole and a shotgun microphone—it just sounds better. But, for the one-person camera crew, that’s not really an option. So, a lavalier mic is often your only choice.